This invention relates to two-part electrical connectors, and particularly to two-part high-speed backplane electrical connectors. More particularly, this invention relates to improvements in shielded two-part high-speed backplane electrical connectors.
Conductors carrying high frequency signals and currents are subject to interference and cross talk when placed in close proximity to other conductors carrying high frequency signals and currents. This interference and cross talk can result in signal degradation and errors in signal reception. Coaxial and shielded cables are available to carry signals from a transmission point to a reception point, and reduce the likelihood that the signal carried in one shielded or coaxial cable will interfere with the signal carried by another shielded or coaxial cable in close proximity. However, at points of connection, the shielding is often lost allowing interference and crosstalk between signals. The use of individual shielded wires and cables is not desirable at points of connections due to the need for making a large number of connections in a very small space. In these circumstances, two-part high-speed backplane electrical connectors containing multiple shielded conductive paths are used.
This design is based on, but not limited to, the industry standard for a two-part high-speed backplane electrical connector for electrically coupling a motherboard (also known as "backplane") to a daughtercard is set forth in the United States by specification IEC 1076-4-101 from the International Electrotechnical Commission. This specification sets out parameters for 2 mm, two-part connectors for use with printed circuit boards. The IEC specification defines a socket connector that includes female receptacle contacts and a header connector that contains male pin contacts configured for insertion into the female receptacle contacts of the socket connector.
A two-part high-speed backplane electrical connector with improved electromagnetic shielding comprises a socket connector and a header connector. The socket connector includes a plurality of connector modules. Each connector module includes an insulated material encasing a plurality of conductive paths. Each connector module is formed to include a plurality of laterally-extending openings which are interleaved with the plurality of conductive paths. The socket connector further includes a plurality of shields including first shield portions extending along first sides of the plurality of connector modules, and second shield portions extending into the laterally-extending openings in the plurality of connector modules to form a coaxial shield around each conductive path.
According to the present invention, a header connector includes a header body formed to include a plurality of first openings and a plurality of second openings. A plurality of signal pins are configured for insertion into the plurality of first openings to form an array of pin contacts extending therefrom. A plurality of shield blades are configured for insertion into the plurality of second openings. Each of the plurality of shield blades is formed to include a generally right angle shielding portion configured to be disposed adjacent to at least one of the plurality of signal pins to form a coaxial shield around each signal pin.
According to a further aspect of the invention, the generally right angle shielding portion of each of the plurality of shield blades includes first and second leg portions. Each of the plurality of second openings in the header body has a generally right angle cross-section for receiving the generally right angle shielding portion of a shield blade. Each generally right angle second opening includes first and second narrowed portions dimensioned to engage the first and second leg portions of the generally right angle shielding portion of a shield blade to hold the shield blade in place.
In accordance with another aspect of the invention, each of the plurality of generally right angle second openings in the header body includes a central portion coupled to first and second end portions by the first and second narrowed portions. The central portion and the first and second end portions of each generally right angle second opening are formed to provide an air gap surrounding the generally right angle shielding portion of a shield blade. The geometry and dimensions of the air gaps, the geometry, dimensions and material of the right angle shielding portions, and the geometry, dimensions and material of the header body surrounding the air gaps are configured to tune the header connector to match a specified impedance.
A protective cap according to still another aspect of the present invention includes a front wall formed to include a plurality of blind holes configured to receive first ends of the signal pins of the header connector when the protective cap is inserted into the header body to protect the signal pins during shipping and handling of the header connector to a customer's facility. The protective cap include a surface configured to engage a portion of the header body surrounding the signal pins, and the blind holes include a surface configured to engage a portion of the signal pins to permit the protective cap to be used as a termination tool to press fit the header connector on the printed circuit board at the customer's facility.
Additional features of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of a preferred embodiment exemplifying the best mode of carrying out the invention as presently perceived.